1. Field of the Invention
The invention relates to mechanisms for reclining the backrests of seats and, more particularly, relates to a mechanism for selectively permitting the reclining of a backrest of a vehicle seat or the like.
2. Discussion of the Related Art
Backrest recliner mechanisms are well known and are commonly used to selectively permit the occupant of a seat to adjust the angle of inclination of the backrest to best suit his or her needs. Such devices typically include a member which operatively connects the seat back to the base of the seat and which, when acted upon by the seat occupant in a designated manner, permits the backrest to recline. One such recliner mechanism is disclosed in U.S. Pat. No. 4,579,386 to Rupp et al. The recliner mechanism disclosed by Rupp et al. includes first and second elongated members each of which is connected to one of the seat base and backrest at a first end and to the other member at the second end. The first and second members are normally locked together by a handle extending therethrough at the point where the members overlap. The handle has one end which is shaped so as to lockingly engage detents formed in a slot formed in the second of the members. The backrest is permitted to recline by rotating the handle to disengage the face of the handle from the detents so that the first and second members can slide relative to one another. When the seat has been reclined to its desired position, the handle is released and is rotated back into engagement with the detents under the operation of a torsion spring.
The recliner mechanism disclosed by Rupp et al. exhibits several disadvantages. For instance, it is relatively complex and requires that the first and second members slidably engage one another over a significant length and that they be connected to one another not only by the handle but also by pins disposed on either side of the handle. Accordingly, assembly of this device requires a relatively high amount of skilled labor. Moreover, any rotation of the handle is resisted not only by the torsion spring but also by the backrest biasing spring which applies significant biasing forces on the face of the handle at all times.